#pragma code_seg("CSAMBA")
#pragma data_seg("DSAMBA")
#pragma bss_seg("BSAMBA")
#pragma const_seg("KSAMBA")
#pragma comment(linker, "/merge:DSAMBA=SAMBA")
#pragma comment(linker, "/merge:CSAMBA=SAMBA")
#pragma comment(linker, "/merge:BSAMBA=SAMBA")
#pragma comment(linker, "/merge:KSAMBA=SAMBA")
/*

    This file is part of the smb++ library

    Copyright (C) 1999  Nicolas Brodu

    nicolas.brodu@free.fr



    This program is free software; you can redistribute it and/or modify

    it under the terms of the GNU General Public License as published by

    the Free Software Foundation; either version 2 of the License, or

    (at your option) any later version.



    This program is distributed in the hope that it will be useful,

    but WITHOUT ANY WARRANTY; without even the implied warranty of

    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

    GNU General Public License for more details.



    You should have received a copy of the GNU General Public License

    along with this program, see the file COPYING; if not, write

    to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge,

    MA 02139, USA.

*/



#include "defines.h"

#ifndef USE_SAMBA



#include "DES.h"

#include <stdio.h>



// official first permutation minus 1 to index from 0 to 63

const unsigned char PC1[56] = {

                        56, 48, 40, 32, 24, 16,  8,

                         0, 57, 49, 41, 33, 25, 17,

	                     9,  1, 58, 50, 42, 34, 26,

                        18, 10,  2, 59, 51, 43, 35,

                        62, 54, 46, 38, 30, 22, 14,

                         6, 61, 53, 45, 37, 29, 21,

                        13,  5, 60, 52, 44, 36, 28,

                        20, 12,  4, 27, 19, 11,  3

};



// official second permutation minus 1 to index from 0 to 55

const unsigned char PC2[48] = {

                           13, 16, 10, 23,  0,  4,

                            2, 27, 14,  5, 20,  9,

                           22, 18, 11,  3, 25,  7,

                           15,  6, 26, 19, 12,  1,

                           40, 51, 30, 36, 46, 54,

                           29, 39, 50, 44, 32, 47,

                           43, 48, 38, 55, 33, 52,

                           45, 41, 49, 35, 28, 31

};



// official left shifts on C[i], D[i], for each K[i]

const unsigned char LSHIFT[16] = {

                  1, 1, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 1

};





// as before, data permutation is given minus 1

const unsigned char IP[64] = {

                        57, 49, 41, 33, 25, 17,  9,  1,

                        59, 51, 43, 35, 27, 19, 11,  3,

                        61, 53, 45, 37, 29, 21, 13,  5,

                        63, 55, 47, 39, 31, 23, 15,  7,

                        56, 48, 40, 32, 24, 16,  8,  0,

                        58, 50, 42, 34, 26, 18, 10,  2,

                        60, 52, 44, 36, 28, 20, 12,  4,

                        62, 54, 46, 38, 30, 22, 14,  6

};



// and now the same for the expansion function

const unsigned char E[48] = {

                           31,  0,  1,  2,  3,  4,

                            3,  4,  5,  6,  7,  8,

                            7,  8, 9, 10, 11, 12,

                           11, 12, 13, 14, 15, 16,

                           15, 16, 17, 18, 19, 20,

                           19, 20, 21, 22, 23, 24,

                           23, 24, 25, 26, 27, 28,

                           27, 28, 29, 30, 31,  0

};





// Substitution boxes, do not reduce by 1 since those are not indexes !

const unsigned char S[8][4][16] = {

         { {14,  4, 13,  1,  2, 15, 11,  8,  3, 10,  6, 12,  5,  9,  0,  7},

           { 0, 15,  7,  4, 14,  2, 13,  1, 10,  6, 12, 11,  9,  5,  3,  8},

           { 4,  1, 14,  8, 13,  6,  2, 11, 15, 12,  9,  7,  3, 10,  5,  0},

           {15, 12,  8,  2,  4,  9,  1,  7,  5, 11,  3, 14, 10,  0,  6, 13}

         },

         { {15,  1,  8, 14,  6, 11,  3,  4,  9,  7,  2, 13, 12,  0,  5, 10},

           { 3, 13,  4,  7, 15,  2,  8, 14, 12,  0,  1, 10,  6,  9, 11,  5},

           { 0, 14,  7, 11, 10,  4, 13,  1,  5,  8, 12,  6,  9,  3,  2, 15},

           {13,  8, 10,  1,  3, 15,  4,  2, 11,  6,  7, 12,  0,  5, 14,  9}

         },

         { {10,  0,  9, 14,  6,  3, 15,  5,  1, 13, 12,  7, 11,  4,  2,  8},

           {13,  7,  0,  9,  3,  4,  6, 10,  2,  8,  5, 14, 12, 11, 15,  1},

           {13,  6,  4,  9,  8, 15,  3,  0, 11,  1,  2, 12,  5, 10, 14,  7},

           { 1, 10, 13,  0,  6,  9,  8,  7,  4, 15, 14,  3, 11,  5,  2, 12}

         },

         { { 7, 13, 14,  3,  0,  6,  9, 10,  1,  2,  8,  5, 11, 12,  4, 15},

           {13,  8, 11,  5,  6, 15,  0,  3,  4,  7,  2, 12,  1, 10, 14,  9},

           {10,  6,  9,  0, 12, 11,  7, 13, 15,  1,  3, 14,  5,  2,  8,  4},

           { 3, 15,  0,  6, 10,  1, 13,  8,  9,  4,  5, 11, 12,  7,  2, 14}

         },

         { { 2, 12,  4,  1,  7, 10, 11,  6,  8,  5,  3, 15, 13,  0, 14,  9},

           {14, 11,  2, 12,  4,  7, 13,  1,  5,  0, 15, 10,  3,  9,  8,  6},

           { 4,  2,  1, 11, 10, 13,  7,  8, 15,  9, 12,  5,  6,  3,  0, 14},

           {11,  8, 12,  7,  1, 14,  2, 13,  6, 15,  0,  9, 10,  4,  5,  3}

         },

         { {12,  1, 10, 15,  9,  2,  6,  8,  0, 13,  3,  4, 14,  7,  5, 11},

           {10, 15,  4,  2,  7, 12,  9,  5,  6,  1, 13, 14,  0, 11,  3,  8},

           { 9, 14, 15,  5,  2,  8, 12,  3,  7,  0,  4, 10,  1, 13, 11,  6},

           { 4,  3,  2, 12,  9,  5, 15, 10, 11, 14,  1,  7,  6,  0,  8, 13}

         },

         { { 4, 11,  2, 14, 15,  0,  8, 13,  3, 12,  9,  7,  5, 10,  6,  1},

           {13,  0, 11,  7,  4,  9,  1, 10, 14,  3,  5, 12,  2, 15,  8,  6},

           { 1,  4, 11, 13, 12,  3,  7, 14, 10, 15,  6,  8,  0,  5,  9,  2},

           { 6, 11, 13,  8,  1,  4, 10,  7,  9,  5,  0, 15, 14,  2,  3, 12}

         },

         { {13,  2,  8,  4,  6, 15, 11,  1, 10,  9,  3, 14,  5,  0, 12,  7},

           { 1, 15, 13,  8, 10,  3,  7,  4, 12,  5,  6, 11,  0, 14,  9,  2},

           { 7, 11,  4,  1,  9, 12, 14,  2,  0,  6, 10, 13, 15,  3,  5,  8},

           { 2,  1, 14,  7,  4, 10,  8, 13, 15, 12,  9,  0,  3,  5,  6, 11}

         }

};



// permutation (after substitution) minus 1 to index from 0 to 31

const unsigned char P[32] = {

                              15,  6, 19, 20,

                              28, 11, 27, 16,

                               0, 14, 22, 25,

                               4, 17, 30,  9,

                               1,  7, 23, 13,

                              31, 26,  2,  8,

                              18, 12, 29,  5,

                              21, 10,  3, 24

};



// final permutation (minus 1)

const unsigned char FP[64] = {

                        39,  7, 47, 15, 55, 23, 63, 31,

                        38,  6, 46, 14, 54, 22, 62, 30,

                        37,  5, 45, 13, 53, 21, 61, 29,

                        36,  4, 44, 12, 52, 20, 60, 28,

                        35,  3, 43, 11, 51, 19, 59, 27,

                        34,  2, 42, 10, 50, 18, 58, 26,

                        33,  1, 41,  9, 49, 17, 57, 25,

                        32,  0, 40,  8, 48, 16, 56, 24

};



// key must be 56 bits

// Anyway, the parity bits introduced in the des-how-to are discarded by the

// first permutation function

DES::DES(const unsigned char* k)

{

	setKey(k);

}



DES::~DES()

{

}



// key must be 56 bits

// Anyway, the parity bits introduced in the des-how-to are discarded by the

// first permutation function

void DES::setKey(const unsigned char* k)

{

	if (!k) return;

	unsigned char *ptr=key;

	int hole=0;

	for (int i=0; i<7; i++) {

		unsigned char c=k[i];

		*(ptr++)=(c&0x80)>>7;

		if ((++hole) % 7 == 0) *(ptr++)=0;

		*(ptr++)=(c&0x40)>>6;

		if ((++hole) % 7 == 0) *(ptr++)=0;

		*(ptr++)=(c&0x20)>>5;

		if ((++hole) % 7 == 0) *(ptr++)=0;

		*(ptr++)=(c&0x10)>>4;

		if ((++hole) % 7 == 0) *(ptr++)=0;

		*(ptr++)=(c&0x08)>>3;

		if ((++hole) % 7 == 0) *(ptr++)=0;

		*(ptr++)=(c&0x04)>>2;

		if ((++hole) % 7 == 0) *(ptr++)=0;

		*(ptr++)=(c&0x02)>>1;

		if ((++hole) % 7 == 0) *(ptr++)=0;

		*(ptr++)=c&0x01;

		if ((++hole) % 7 == 0) *(ptr++)=0;

	}



	unsigned char C[28]; // one bit by byte, simpler algorithm...

	unsigned char D[28]; // one bit by byte, simpler algorithm...

	// Initial permutation of the key

#ifdef _WIN32

	for (i=0; i<28; i++) {

#else

	for (int i=0; i<28; i++) {

#endif

		C[i]=key[PC1[i]];

		D[i]=key[PC1[i+28]];

	}



	unsigned char concat[56];

	// calculate the 16 keys

#ifdef _WIN32

	for (i=0; i<16; i++) {

#else

	for (int i=0; i<16; i++) {

#endif

		// do LSHIFT[i] shifts

		for (int j=0; j<LSHIFT[i]; j++) {

			// do the shift

			unsigned char savC = C[0];

			unsigned char savD = D[0];

			for (int l=0; l<27; l++) {

				C[l]=C[l+1];

				D[l]=D[l+1];

				concat[l]=C[l];

				concat[l+28]=D[l];

			}

			C[27]=savC;

			D[27]=savD;

			concat[27]=savC;

			concat[55]=savD;

		}

		// new permutation => give key

#ifdef _WIN32

		for (j=0; j<48; j++) {

#else

		for (int j=0; j<48; j++) {

#endif

			K[i][j]=concat[PC2[j]];

		}



	}

}





// Encrypt (encdec=0) or decrypt (encdec=1)

void DES::doIt(unsigned char* data, const unsigned long length, int encdec)

{

	unsigned char plain[64];

	unsigned char L[32];

	unsigned char R[32];

	unsigned char ER[48]; // expanded R xored with key

	unsigned char* dataIndex=data;

	int i,j;



	int len=length;

	while (len>=8) {

		// generate 64 bit "plain text" bloc

		unsigned char *ptr=plain;

		for (i=0; i<8; i++) {

			unsigned char c=*(dataIndex+i);

			*(ptr++)=(c&0x80)>>7;

			*(ptr++)=(c&0x40)>>6;

			*(ptr++)=(c&0x20)>>5;

			*(ptr++)=(c&0x10)>>4;

			*(ptr++)=(c&0x08)>>3;

			*(ptr++)=(c&0x04)>>2;

			*(ptr++)=(c&0x02)>>1;

			*(ptr++)=c&0x01;

		}



		// Initial permutation of the data block

		for (i=0; i<32; i++) {

			L[i]=plain[IP[i]];

			R[i]=plain[IP[i+32]];

		}

		

		// Apply the 16 keys

		for (i=0; i<16; i++) {

			// expand R and xor with key number i

			for (j=0; j<48; j++) {

				ER[j] = R[E[j]] ^ K[encdec?15-i:i][j];

			}

			unsigned char* ERIndex=ER;  // where to get the values

			unsigned char* ERIndexS=ER; // where to substitute (4 bits wide only)

			// apply the substitutions

			for (j=0; j<8; j++) {

				unsigned char c = S[j]

					[((*ERIndex)<<1)|(*(ERIndex+5))]

					[((*(ERIndex+1))<<3)|((*(ERIndex+2))<<2)|((*(ERIndex+3))<<1)|(*(ERIndex+4))];

				*(ERIndexS++)=(c&0x08)>>3;

				*(ERIndexS++)=(c&0x04)>>2;

				*(ERIndexS++)=(c&0x02)>>1;

				*(ERIndexS++)=c&0x01;

				ERIndex+=6;

			}

			// permute again and xor with L

			// assign new values for R and L

			for (j=0; j<32; j++) {

				unsigned char tmp = ER[P[j]] ^ L[j];

				L[j] = R[j];

				R[j] = tmp;

			}

		} // end of apply all keys



		// append R, L => plain (no need to declare another 64 bytes array)

		for (i=0; i<32; i++) {

			plain[i]=R[i];

			plain[i+32]=L[i];

		}

		// Final permutation, put result back into "data"

		for (i=0; i<8; i++) {

			j=i<<3;

			*(dataIndex++) = plain[FP[j+7]]

				| (plain[FP[j+6]] << 1)

				| (plain[FP[j+5]] << 2)

				| (plain[FP[j+4]] << 3)

				| (plain[FP[j+3]] << 4)

				| (plain[FP[j+2]] << 5)

				| (plain[FP[j+1]] << 6)

				| (plain[FP[j]] << 7);

		}



		len-=8;

	} // of while len>=8

}



// Data should always be aligned to a 64 bit multiple

// If not, discard the junk (hence force the caller to paddle...)

void DES::encrypt(unsigned char* data, const unsigned long length)

{

	doIt(data,length,0);

}



void DES::decrypt(unsigned char* data, const unsigned long length)

{

	doIt(data,length,1);

}

#endif

#pragma code_seg()
#pragma data_seg()
#pragma bss_seg()
#pragma const_seg()

